4、Hibenrate中HQL的10中查询方式

二、具体事例如下：

2.0 编写如下sql语句

 create table teacher(tid number not null primary key,tname varchar2(20));
 create sequence seq_teacher;
 insert into teacher values(seq_teacher.nextval,'holly');
 insert into teacher values(seq_teacher.nextval,'石头');
 commit;
 insert into teacher values(seq_teacher.nextval,'holly1');
 insert into teacher values(seq_teacher.nextval,'holly2');
 commit;

2.1 创建如下的javaweb项目并添加jar文件

2.2 在项目的src下创建hibernate.cfg.xml主配置文件

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd" >
 <hibernate-configuration>
   <session-factory>
      <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
      <property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:orcl</property>
      <property name="connection.username">scott</property>
      <property name="connection.password">tiger</property>
      <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>
      <property name="show_sql">true</property>
      <property name="format_sql">true</property>
      <mapping resource="com/entity/Teacher.hbm.xml"/>
   </session-factory>
 </hibernate-configuration>

2.3 在项目的com.entity包下创建Teacher.java类

 package com.entity;

 public class Teacher {
     private int tid;
     private String tname;

     public Teacher() {
     }

     public Teacher(String tname) {
         this.tname = tname;
     }

     public Teacher(int tid, String tname) {
         this.tid = tid;
         this.tname = tname;
     }

     public int getTid() {
         return tid;
     }

     public void setTid(int tid) {
         this.tid = tid;
     }

     public String getTname() {
         return tname;
     }

     public void setTname(String tname) {
         this.tname = tname;
     }

     @Override
     public String toString() {
         return "Teacher [tid=" + tid + ", tname=" + tname + "]";
     }

 }

2.4 在项目的com.entity包下创建Teacher.hbm.xm文件

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
 <hibernate-mapping>
 <class name="com.entity.Teacher" table="TEACHER">
   <id name="tid" type="java.lang.Integer" column="TID">
     <generator class="sequence">
        <param name="sequence">seq_teacher</param>
     </generator>
   </id>
   <property name="tname" type="java.lang.String" column="TNAME"/>
 </class>
 </hibernate-mapping>

2.5 在项目的com.util包下创建HibernateUtil.java类

 package com.util;

 import org.hibernate.HibernateException;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.cfg.Configuration;

 public class HibernateUtil {
     private static ThreadLocal<Session> thread=new ThreadLocal<Session>();
     private static Configuration config=null;
     private static SessionFactory factory=null;

     static{
         try {
             config=new Configuration().configure("/hibernate.cfg.xml");
             factory=config.buildSessionFactory();
         } catch (HibernateException e) {
             System.out.println("读取配置文件或创建工厂失败");
             e.printStackTrace();
         }
     }

     public static Session getSession(){
         Session session =thread.get();
         if(session==null){
             session =factory.openSession();
             thread.set(session);
         }
         return session;
     }
     public static void closeSession(){
         Session session =thread.get();
         thread.set(null);
         session.close();

     }

 }

2.6 在项目的com.dao包下创建TeacherDao.java类

 package com.dao;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Query;
 import org.hibernate.Session;

 import com.entity.Teacher;
 import com.util.HibernateUtil;

 public class TeacherDao {
     /**
      * 1.iterate() 延时加载查询一堆
      * 得到1+N条sql
      * 1是查询所有的sql
      * n根据id查询的n条sql
      * 延迟加载(用时在查询),关闭session的时机是读取完数据之后再关闭
      */
     public static Iterator<Teacher> hqlItertor() {
         Session session=HibernateUtil.getSession();
         //定义hql语句
         String hql="from Teacher";

         //创建Query查询接口对象
         Query query=session.createQuery(hql);

         //使用list方法查询所有返回list集合
         Iterator<Teacher> it=query.iterate();

         return it;
     }
     /**
      *  2. list()立即加载
      * 一条sql
      * 立即加载(一次性查询出所有内容(关联)放入内存)
      *
      */
     public static List<Teacher> hqlList() {
         Session session=HibernateUtil.getSession();
         //定义hql语句
         String hql="from Teacher";

         //创建Query查询接口对象
         Query query=session.createQuery(hql);

         //使用list方法查询所有返回list集合
         List<Teacher> list=query.list();

         HibernateUtil.closeSession();
         return list;

     }
     /**
      * 3.根据条件查询返回集合
      * @param tname
      * @return
      */
     public static List<Teacher> hqlIf(String tname) {
         Session session=HibernateUtil.getSession();
         //定义hql语句
         String hql="from Teacher where tname='"+tname+"'";

         //创建Query查询接口对象
         Query query=session.createQuery(hql);

         //使用list方法查询所有返回list集合
         List<Teacher> list=query.list();

         HibernateUtil.closeSession();
         return list;
     }
     /**
      * 4. 占位符的使用(模糊查询)
      * @param string
      * @return
      */
     public static List<Teacher> hqlLike(String name) {
         Session session=HibernateUtil.getSession();
         //定义hql语句
         String hql="from Teacher where tname like ?";

         //创建Query查询接口对象
         Query query=session.createQuery(hql);
         String str="%"+name+"%";
         query.setString(0, str);

         //使用list方法查询所有返回list集合
         List<Teacher> list=query.list();

         HibernateUtil.closeSession();
         return list;
     }
     /**
      * 5. 按照参数名称使用(模糊查询)
      * @param string
      * @return
      */
     public static List<Teacher> hqlLikeName(String name) {
         Session session=HibernateUtil.getSession();
         //定义hql语句
         String hql="from Teacher where tname like :pname";

         //创建Query查询接口对象
         Query query=session.createQuery(hql);
         String str="%"+name+"%";
         query.setString("pname", str);

         //使用list方法查询所有返回list集合
         List<Teacher> list=query.list();

         HibernateUtil.closeSession();
         return list;
     }
     /**
      * 6. 条件查询绑定任意类型的参数:命名参数
      * @param string
      * @return
      */
     public static List<Teacher> hqlSetParam(String name) {
         Session session=HibernateUtil.getSession();
         //定义hql语句
         String hql="from Teacher where tname like :pname";

         //创建Query查询接口对象
         Query query=session.createQuery(hql);
         String str="%"+name+"%";

         query.setParameter("pname", str);

         //使用list方法查询所有返回list集合
         List<Teacher> list=query.list();

         HibernateUtil.closeSession();
         return list;
     }
     /**
      * 7. 条件查询绑定任意类型的参数:占位符
      * @param string
      * @return
      */
     public static List<Teacher> hqlSetParamXx(String name) {
         Session session=HibernateUtil.getSession();
         //定义hql语句
         String hql="from Teacher where tname like ?";

         //创建Query查询接口对象
         Query query=session.createQuery(hql);
         String str="%"+name+"%";

         query.setParameter(0, str);

         //使用list方法查询所有返回list集合
         List<Teacher> list=query.list();

         HibernateUtil.closeSession();
         return list;
     }

     /**
      * 8.条件动态:通过对象属性去给命名参数赋值
      * @param name
      * @return
      */
     public static List<Teacher> hqlSetProte(Teacher teacher) {

         Session session=HibernateUtil.getSession();
         //定义hql语句
         StringBuilder hql=new StringBuilder("from Teacher as t where 1=1");

         if(teacher.getTname()!=null){
             hql.append(" and t.tname=:tname");
         }

         //创建Query查询接口对象
         Query query=session.createQuery(hql.toString());
         query.setProperties(teacher);

         //使用list方法查询所有返回list集合
         List<Teacher> list=query.list();

         HibernateUtil.closeSession();
         return list;
     }
     /**
      * 9.查询单条数据
      * @return
      */
     public static Teacher hhqlGetTeacher(String name) {
         Session session=HibernateUtil.getSession();
         //定义hql语句
         String hql="from Teacher where tname=:pname";

         //创建Query查询接口对象
         Query query=session.createQuery(hql.toString());
         query.setParameter("pname", name);

         //使用
         Teacher teacher=(Teacher) query.uniqueResult();

         HibernateUtil.closeSession();
         return teacher;
     }
     /**
      * 10. 分页查询
      * @param i
      * @param j
      * @return
      */
     public static List<Teacher> hqlPage(int pageSize, int pageNo) {
         Session session=HibernateUtil.getSession();

         //1.获取中条数
         //定义中条数的hql语句
         String hqlcount="select count(*) from Teacher";
         Query countQuery=session.createQuery(hqlcount);

         //uniqueResult()得到总条数
         Integer totalCount=Integer.parseInt(countQuery.uniqueResult().toString());
         System.out.println("总条数:"+totalCount);

         //2.计算总页数
         int totalPage=totalCount%pageSize==0?totalCount/pageSize:totalCount/pageSize+1;
         System.out.println("总页数:"+totalPage);

         //3.查询的最大记录数(每页查询几条)
         String hql="from Teacher";
         Query query=session.createQuery(hql);

         query.setMaxResults(pageSize);

         //4.确定查询查询的起点
         query.setFirstResult((pageNo-1)*pageSize);

         //5.查询分页数据
         List<Teacher> list=query.list();
         HibernateUtil.closeSession();
         return list;
     }
 }

2.7 在项目的com.test包下创建Test.java类

 package com.test;

 import java.util.Iterator;
 import java.util.List;

 import com.dao.TeacherDao;
 import com.entity.Teacher;
 import com.util.HibernateUtil;

 public class Test {

     public static void main(String[] args) {
 //        System.out.println("--------------1.使用list查询所有-----------");
 //        List<Teacher> list=TeacherDao.hqlList();
 //        for (Teacher teacher : list) {
 //            System.out.println(teacher);
 //        }
 //        System.out.println("--------------2.使用Itertor查询所有-----------");
 //        Iterator<Teacher> it=TeacherDao.hqlItertor();
 //        Teacher te=null;
 //        while (it.hasNext()) {
 //            te=it.next();
 //            System.out.println(te);
 //        }
 //        HibernateUtil.closeSession();
 //
 //        System.out.println("----------3.条件拼接查询-----------");
 //        List<Teacher> iflist=TeacherDao.hqlIf("holly");
 //        for (Teacher teacher : iflist) {
 //            System.out.println(teacher);
 //        }
 //
 //        System.out.println("----------4.条件查询模糊查询:按照参数位置-----------");
 //        List<Teacher> likelist=TeacherDao.hqlLike("holly");
 //        for (Teacher teacher : likelist) {
 //            System.out.println(teacher);
 //        }
 //        System.out.println("----------5.条件查询模糊查询:按照名称-----------");
 //        List<Teacher> likeNamelist=TeacherDao.hqlLikeName("holly");
 //        for (Teacher teacher : likeNamelist) {
 //            System.out.println(teacher);
 //        }

 //        System.out.println("----------6.条件查询绑定任意类型的参数-----------");
 //        List<Teacher> SetParamlist=TeacherDao.hqlSetParam("holly");
 //        for (Teacher teacher : SetParamlist) {
 //            System.out.println(teacher);
 //        }
 //        System.out.println("----------7.条件查询绑定任意类型的参数:占位符-----------");
 //        List<Teacher> SetParamXx=TeacherDao.hqlSetParamXx("holly");
 //        for (Teacher teacher : SetParamXx) {
 //            System.out.println(teacher);
 //        }
         System.out.println("----------8.条件动态:命名参数-----------");
 //        Teacher te=new Teacher("holly");
 //        List<Teacher> SetProte=TeacherDao.hqlSetProte(te);
 //        for (Teacher teacher : SetProte) {
 //            System.out.println(teacher);
 //        }

         System.out.println("------------9.查询单条数据-----------");
 //        Teacher teacher=TeacherDao.hhqlGetTeacher("holly");
 //        System.out.println(teacher);

         System.out.println("---------10.分页查询------------");
         List<Teacher> list=TeacherDao.hqlPage(2,2);
         System.out.println("页面大小:"+2+",当前页:"+2);
         for (Teacher teacher : list) {
             System.out.println(teacher);
         }

     }

 }

2.8  效果自己试试就知道